Fill a large pot with water, sprinkle in some salt and bring to a boil. Add the kale and cook for 2 minutes, then remove with a slotted spoon and shock with cold water.

Bring the same water back up to a boil, add the rigatoni and cook according to the package directions.

In a food processor, add the blanched kale, walnuts, lemon zest, lemon juice, garlic and some salt and pepper. Start pulsing everything together and slowly add the olive oil. Once combined, transfer the mixture to a bowl and stir in the Parmigiano-Reggiano.

Drain the pasta, reserving 1/2 cup of the starchy pasta cooking water. Add the pasta back to the pot and add in the pesto and reserved cooking water. Toss everything together until it's all combined.

Plate on a large platter and sprinkle over some extra cheese and some freshly grated black pepper.